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(Ho Model.)

A. BERNSTEIN.

` ELECTRIC SWITCH.

No. 343,266. Patented June 8, 1886.

UNITED STATES PATENT OFrIci-r.

ALEXDER BERSTE, OF LONDON, FNGLAND.

ELECTRlC SWITCH.

EPECIFICATION fcrming part of Letters Patent NO. 343,266, datecl June 9, 1886.

Application filed March Al, 1856.

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Be it known that I, ALEXNDER BnRN- srEiN, a subject of the Emperor 01' Germany, residing at London, England, have inventcd new and useful lmprovemcnts in Electric Switches, of, which the following is a specification. w

My invention relates to certain improvements in electric switches intended to be used in electric circuits, such as those in which a large number of devices-such asglow-lamps are arranged in series on one common conductor.

The improved switch is adapted for use wherever an electric device is to be included in or exclnded from the main current,and itis especially suitable for use in connection with a system of electric lighting such as is described in the specification of my former English Letters Patent No. 6,075,dated December 20, 1882. In electric-lighting ci1'euitssuch as are referred to in the specification of my said former Letters Patent-a switch is required whcrever the currententers and leaves a house to be lighted, and in describing my improved switch I shall suppose the same to be used in a place which requires that the switch shall serve the following` purposes, delz'cc': To allow the house-circuit to be passed by the current or a short Circuit to be made in order to prevent the current from passing through the house. In the latter case it is t'urther desirable that the house-circuit shall be entirely disconnected from the main circuit, so that any repairs or alterations can be effected inside the house without danger,even if the main circuit should have a dcfective insulation. It is moreover necessary to prevent any interruption of the eircuit in case the house-circuit is not complete at the time at which it is intended to turn the current into the same, and the attainment of this object is the main feature of my invention. For this purpose I arrange the switch in such a man ncr that the switch-lever, after leaving` the off/'i position, in which the house-Circuit is short circuited, and before coming into the 0117? position, in which the current would pass through the house, can take an intermediate position,in which the main current will divide itselfinto two branches, one part of the curi l i Serial X0. 193,938. (No model.)

rent passiug through a permanent resistance connected with the switch, and the other partI passing through the honse!circuit,if the same is complete. lf the latter be the case, then the current in the house-circuit will excite an electro-inaguet lthe armature of which is attracted. This armature, if it were not attracted, would interfere with a further movement of the switch-lever from the said intermediate position, and in this way the lever is prevented from coming into the on position, except when the house-Circuit is complete.

In order to enable my invention to be fully understood, I will proceed to describe the same by reference to the accompanying drawings, in which- Figure l rcpresents a plan of an electric switch constructcd according to my invention, and Fig. 2 is a cross-section on line 2 2 of Fig. l.

a represents a circular box of insulating material, on the upper edge ot' 'which three contact pieces or strips of metal, l), c, and (Z, are fastencd.

Zis the switch-lever, made of metal. This lever turns on a central pivot and can occupy three different positions, indicated in Fig. 1 by the dotted lines 1 1, 2 2, and 3 3, respectively. In the position marked 1 l the lever Z connects the strip b with the strip (7. In the position marked 2 2 the strip c is connected by the lever 7 with the strip d, andin the position marked 3 3 the lever Z rests on insulating-pieces at both ends.

e and f are two at Springs of metal, the i'ree ends of which rest, respectively, on the strips Z) and (Z. These springs are in practice generally placed concent-ric with the top edge or rim of the box (i, but are shown in the drawings placed at an angle thereto for the sake of clearness.

The lever Z, as shown in Fig. 2, carries on its upper side,at its two ends, the pieces of insulating material g' and h. Then the lever Z is placed in the position marhed l 1, as hereinbefore described, it conueots the strip b with the strip (Z, and as the strip b forms one terminal of the main circuit Q and the strip (Z forms the other terminal thereof, it follows that the two ends of the circuit are then directly connected.

The sirino` c :forms one IOO terminal of the house-Circuit o, and the spring f forms the other terminal of the same. Then the lever l is moved into the position marked 1 1, it lifts the spring c from the strip b and the springf from the strip d, thereby causing the two Springs e and f to rest on the two pieces of insulating material hand g, respectively, attached to the ends of the lever Z, and the house-circuit o will be entirely out of electrical connection with the main circuit q.

In order to prevent any interruption i-n the circuit in case the house-circuit should not be I completed, as hereinbefore mentioned, I connect the two contact-pieces b and c with each other by means of.a permanent resistancepiece, r, which represents a certain part of the resistance of the house Circuit o. This lattercircuit, o, includes an electro-magnet, m, which is placed inside the box a, as shown. The armature n of the electro-magnet m carries a pin, p, which is placed in such a way that if the armature be not attracted the pin p will be on alevel with the lever l,- but if the armature be attracted, then the pin will be below thelever Z, and will not prevent the free movement of the lever. If, then, the lever l be placed in lthe intermediate position, (marked 2 2,) part of the current will pass through the permanent resistance-piece r, and part will pass through the house-circuit o, if the same is complete. Consequently the armature n will be moved downward,and the lever Z can now be moved into the position marked 3 3, in. which position it will be entirely insulated, and the whole current will then pass through the house-circuit o. If, however, the

house-Circuit o had been interrupted, it would have been impossible to move the lever l into the position marked 3 3, and a break in the main circuit q would have been in this way prevented.

Instead of employing the electro-magnet m, any other suitable known device-such as a galvanonieter-can be used, which merely indicates the existence of a current in the housecircuit o, thereby showing that the lever Z should not be moved into the position marked 8 3.

The switch which I have described as a main house-switch is also adapted to be used in connection with every single electric device, such as glow-lamps or other like devices, which are placed in the house-Circuit.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is- 1. In an electric switch, the combination,

wit-h a permanent resistance arranged to act as a temporary pass for the main current, of a suitable electro-magnetic device--such as that herein described-for indicatingacurrent in the circuit, which is int-ended to be included in the main circuit, as hereinbefore described.

2. In an electric switch, t'he combination, with a permanent resistance arranged to act as a temporary pass for the main current, of an electro-magnet the armature of which operatfs so as to arrest the movement of the switch-lever in case of interruption of the circuit, which it is intended should be included in the main circuit, as hereinbefore described.

ALEXNDER BERNSTE IN.

Witnesses:

G. F. REDFERN, A. S. KLUTT. 

